1. Field of the Invention
The present invention relates to a wheel cap or a hub cap made mainly of resin and installed on an automobile wheel.
2. Description of Related Art
A wheel cap has been installed on an automobile wheel mainly in order to impart decorativeness to the automobile wheel. The wheel cap has engagers that are elastically deformable and disposed on its rear surface, and the cap is installed detachably on the automobile wheel by the elastic force of the engagers.
A variety of wheel caps made mainly of resin have recently been installed on automobile wheels. However, the engagers made of resin do not produce a sufficient elastic force. Accordingly, a ring-shaped holder made of metal has been employed. With the help of the holder, the engagers are pressed and held onto the inner surface of the automobile wheel.
For instance, Japanese Unexamined Patent Publication No. 107601/1986 discloses a wheel cap as illustrated in FIG. 16. The wheel cap comprises a disk-shaped resin base 100, a plurality of engagers 101 integral with that base disposed in series at intervals in a circumferential direction on the rear surface of the base and protruding therefrom in a direction substantially parallel to the axis thereof or perpendicular to the plane of the base, and a ring-shaped holder 102 made of metal, held on an inner peripheral side of the engagers 101 and urging the engagers outward in a radial direction. In the wheel cap, the holder 102 engages with a groove 103 formed on the inner peripheral surface of the engagers 101 and urges the latter so that they are pressed against and engaged with the inner peripheral surface of a wheel 104. Thus the wheel cap is held on the wheel 104.
In the conventional wheel cap, there is anxiety and possibility that the wheel cap might come off the wheel 104 due to vibrations, shocks or the like during traveling. The wheel cap might come off the wheel when the wheel cap is moved eccentrically with respect to the wheel 104 by shocks or the like and the engagers 101 are considerably deformed. If such is the case, since the holder 102 might come out of the groove 103 of the engagers 101, and since the force exerted by the holder 102 and urging the engagers 101 might become weaker, the wheel cap might come off the wheel 104.